Chitosan

Chitosanis a linear polysaccharide composed of randomly distributed β-(1-4)-linkedD-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit).It is made by treating shrimp and other crustacean shells with the alkalisodium hydroxide.   Chitosan has a number of commercial and possiblebiomedical uses. It can be used in agriculture as a seed treatment andbiopesticide, helping plants to fight off fungal infections. In winemaking itcan be used as a fining agent, also helping to prevent spoilage. In industry,it can be used in a self-healing polyurethane paint coating. In medicine, itmay be useful in bandages to reduce bleeding and as an antibacterial agent; itcan also be used to help deliver drugs through the skin.   More controversially,chitosan has been asserted to have use in limiting fat absorption, which wouldmake it useful for dieting, but there is evidence against this. Other uses ofchitosan that have been researched include use as a soluble dietary fiber.